TWI491106B - Wireless communication antenna and wireless communication device - Google Patents

Description

Wireless communication antenna and wireless communication device

The present invention relates to a wireless communication antenna and a wireless communication device for transmitting a signal (electromagnetic wave) at a short distance.

Conventionally, a signal transmission device that performs signal transmission using a plurality of substrates each forming a resonator has been known. For example, Patent Document 1 discloses that a resonator is formed on each of the different substrates, and the resonators are electromagnetically coupled to each other to form a two-stage filter for signal transmission.

Patent literature

Patent Document 1 JP-A-2008-67012

Generally, in a wireless communication antenna using a resonator, components of electromagnetic waves radiated from the antenna include components that propagate to a distant place and components that propagate only to the vicinity of the antenna. At this time, the intensity of the component that propagates to the far side is inversely proportional to the distance r from the antenna, and only the intensity of the component propagating to the vicinity of the antenna is inversely proportional to the square of the distance r from the antenna or the cube. On the other hand, in order to realize high-speed wireless communication, it is advantageous to widen the frequency bandwidth of the signal. At this time, in order to use a wide-band signal, interference with the frequency and frequency bandwidth of a predetermined wireless communication system must be avoided (according to the limitation of the radio wave method). As described above, the component of the electromagnetic wave radiated from the antenna includes a component that propagates to a distant place, but for example, in the case of performing wireless communication from a short distance of about several millimeters to several centimeters, in order to transmit The components that are broadcast to the far side are as small as possible, and the radiated power of the antenna must be minimized. By using a weak transmission power that does not violate the degree of the radio wave method, the frequency and frequency bandwidth restrictions do not exist, and high-speed wireless communication at close range can be realized. In the conventional resonator structure described in Patent Document 1, it is difficult to prevent a signal (electromagnetic wave) from leaking to a distant place under high-speed wireless communication at a short distance.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a wireless communication antenna and a wireless communication device capable of preventing leakage of signals (electromagnetic waves) to a distant place.

The wireless communication antenna according to the present invention includes: the first and second resonators each having an open end and arranged in parallel with each other so that the open ends thereof are opposed to each other; and the capacitor is coupled to the opposite end Between the open ends.

The wireless communication device of the present invention includes: a first antenna that transmits a signal; and a second antenna that receives a signal transmitted from the first antenna; and the wireless antenna for use in the present invention constitutes a first antenna .

Further, the first antenna may further have a function of receiving a signal, and the second antenna further has a function of transmitting a signal, and the signal is transmitted and received bidirectionally between the first antenna and the second antenna, and the present invention is respectively described above. The antenna for wireless communication constitutes a first antenna and a second antenna.

In the wireless communication antenna or the wireless communication device according to the present invention, the first and second resonators are arranged in parallel with each other so that the respective open ends are opposed to each other, and the opposite open ends are connected via a capacitor. On the other hand, in the fundamental resonance mode (the lowest-order resonance mode with the lowest resonance frequency), the directions of the currents flowing in the first and second resonators are opposite (differential resonance mode). Therefore, in the fundamental resonance mode, the currents flowing in the first and second resonators cancel each other, and the radiated power to the far side becomes small.

In the wireless communication antenna of the present invention, the first and second resonators can be configured, for example, by a line resonator using a conductor line. The capacitor can be formed by an electrode pattern of a conductor formed on the open end sides of the first and second resonators.

Further, the capacitors of the elements different from the first and second resonators may constitute a capacitor.

Further, in the wireless communication antenna of the present invention, the first λ/2 resonator ((1/2) wavelength resonator) having both ends as the open end may constitute the first resonator, and the second λ/ having both ends as the open ends. 2 The resonator constitutes a second resonator. In this case, the first capacitor and the second capacitor constitute a capacitor, and the first capacitor is connected to one open end of the first resonator and one open end of the second resonator; and the second capacitor and the first resonator are connected The other open end is connected to the other open end of the second resonator.

In the case where the first and second resonators are constituted by the λ/2 resonator, for example, in the first λ/2 resonator, one end of the signal source is connected at a position spaced apart from the resonance center position, and the other end of the signal source is connected. Grounding is preferred. Alternatively, the first λ/2 resonator may be connected to one end of the signal source at a predetermined interval from the resonance center position, and the other end of the signal source may be connected to the resonance center position of the second λ/2 resonator.

Moreover, the antenna for wireless communication of the present invention can also be made with one end A first λ/4 resonator ((1/4) wavelength resonator) having an open end and a short-circuited end at the other end constitutes a first resonator, and is constituted by a second λ/4 resonator having one end as an open end and the other end as a short-circuit end. The second resonator.

In this case, for example, one end of the signal source is connected at a position spaced apart from the short-circuit end of the first λ/4 resonator, and the other end of the signal source is preferably grounded.

Further, in the wireless communication antenna or the wireless communication device of the present invention, "signal transmission" is not limited to signal transmission such as transmitting/receiving analog signals or digital signals, and includes power transmission such as power transmission/reception.

According to the wireless communication antenna or the wireless communication device of the present invention, the first and second resonators are arranged in parallel with each other so that the open ends of the first and second resonators face each other, and the opposite ends of the open ends are connected via the capacitor. Therefore, the fundamental resonance mode in which the directions of the currents flowing through the first and second resonators are opposite is obtained. Therefore, in the fundamental resonance mode, the currents flowing in the first and second resonators cancel each other out, and since the radiated power to the far side becomes small, the signal transmission in the frequency band corresponding to the fundamental resonance mode can prevent the signal from leaking to the far side. (Electromagnetic wave).

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<First Embodiment> [Basic composition of antenna for wireless communication]

Fig. 1 shows an antenna for wireless communication according to a first embodiment of the present invention The basic composition. The wireless communication antenna includes a first λ/2 resonator 11 (first resonator), a second λ/2 resonator 12 (second resonator), a first capacitor 20, and a second capacitor 30.

The two ends of the first λ/2 resonator 11 and the second λ/2 resonator 12 are open ends, and are arranged in parallel with each other so that the open ends of each other face each other (for example, in parallel or in the same plane) Directional parallel configuration). The first capacitor 20 and the second capacitor 30 are connected between the first open ends of the first λ/2 resonator 11 and the second λ/2 resonator 12.

More specifically, the first capacitor 20 is connected to one of the open ends of the first λ/2 resonator 11 and one of the open ends of the second λ/2 resonator 12. The first capacitor electrode 21 of the first capacitor 20 is connected to one of the open ends of the first λ/2 resonator 11. The second capacitor electrode 22 of the first capacitor 20 is connected to one of the open ends of the second λ/2 resonator 12.

Further, the second capacitor 30 is connected to the other open end of the first λ/2 resonator 11 and the other open end of the second λ/2 resonator 12. The first capacitor electrode 31 of the second capacitor 30 is connected to the other open end of the first λ/2 resonator 11. The second capacitor electrode 32 of the second capacitor 30 is connected to the other open end of the second λ/2 resonator 12.

[Basic actions and functions of antennas for wireless communication]

Fig. 2 shows the state of charge distribution and current vector of the wireless communication antenna in the fundamental resonance mode (the lowest resonance mode of the resonance frequency). Fig. 3(A) shows the distribution of the electric field E and the current vector (i) of the first λ/2 resonator 11 in the fundamental resonance mode, and Fig. 3(B) shows the second λ/2 resonance in the fundamental resonance mode. The electric field distribution of the device 12 and the state of the current vector.

In the wireless communication antenna, the first and second λ/2 resonators 11 and 12 are arranged in parallel with each other (parallel arrangement) so that the open ends of each other face each other, and the first and the opposite open ends pass through the first and The second capacitors 20 and 30 are connected to each other, whereby the electric field intensity distribution as shown in the third (A) and (B) is obtained in the fundamental resonance mode. In other words, when the capacitance Cint1 of the first capacitor 20 is the same as the capacitance Cint2 of the second capacitor 30, and the physical center line 16 of the resonator is the resonance center (zero potential), the first λ/2 resonator 11 is The electric field distribution of the 2nd λ/2 resonator 12 is opposite to each other. Therefore, in the fundamental resonance mode, as shown in FIG. 2, in the first λ/2 resonator 11 and the second λ/2 resonator 12, the directions of the current i flowing are opposite to each other (becoming a differential resonance mode). Therefore, in the fundamental resonance mode, the current flowing between the first λ/2 resonator 11 and the second λ/2 resonator 12 cancels each other, and the radiant power to the far side becomes small. Therefore, it is possible to prevent the signal (electromagnetic wave) from leaking to a distant place in signal transmission in the frequency band corresponding to the fundamental resonance mode.

Generally, in the wireless communication antenna using the resonator, the electromagnetic wave component radiated from the antenna includes a component that propagates to a distant place and a component that propagates only to the vicinity of the antenna. The components that are transmitted to the far side radiate to the outside in the form of energy, and therefore do not return to the input resonator, so they become losses (radiation loss). On the other hand, the energy that is only transmitted to the components in the vicinity of the antenna is not radiated to the outside, but is stored in the space near the resonator as the reactance energy. Therefore, even if the radiated power of the component that is transmitted to the far side is zero, if the two wireless communication antennas are close to each other, each of the two wireless communication antennas is configured to have a component that propagates only to the vicinity. Electromagnetic coupling is performed, and reactance coupling is performed. in In this case, between the resonators constituting the two wireless communication antennas, the energy exchange by only the components that have propagated to the vicinity starts, and becomes a resonance state, forming a hybrid resonance mode, and can be between the different resonators. (between two wireless communication antennas) to transmit signals. Therefore, for example, when the wireless communication antenna shown in FIG. 1 is used as a coupler, the two wireless communication antennas having the configuration shown in FIG. 1 are used to make the radiation power become as close as possible. Small, and a wireless communication device that utilizes only reactive reactance transmission can be realized. Therefore, high-speed wireless communication at a short distance can be realized while avoiding interference with the frequency and frequency bandwidth of the existing wireless communication system.

[Connection method with signal source (excitation method of resonator)]

Fig. 4 is a view showing a first example of a method of exciting a resonator in the wireless communication antenna shown in Fig. 1. In the first example, in the first λ/2 resonator 11, one end of the signal source 13 (the first connection line 15) is connected to the position 17 at a predetermined distance x0 from the resonance center position, and the other end of the signal source 13 (the 2 connection line 14) grounded. Further, when the capacitance Cint1 of the first capacitor 20 is the same as the capacitance Cint2 of the second capacitor 30, the physical center line 16 of the resonator becomes the resonance center (zero potential). In this case, one end of the signal source 13 is connected at a position 17 at a distance x0 from the center line 16.

Fig. 5 shows a second example of the resonator of the excitation method of the resonator. In the second example, the first λ/2 resonator 11 is connected to one end (first connection line 15) of the signal source 13 at a position 17 that is apart from the resonance center position by a predetermined distance x0, and is also in the second λ/2 resonator 12 The resonance center position is connected to the other end of the signal source 13 (second connection line 14). In addition, if the first capacitor The capacitance Cint1 of the capacitor 20 is the same as the capacitance Cint2 of the second capacitor 30, and the physical center line 16 of the resonator becomes the resonance center (zero potential). In this case, one end of the signal source 13 is connected at a position 17 at a distance x0 from the center line 16, and the other end of the signal source 13 is connected at the position of the center line 16.

The distance x0 in FIGS. 4 and 5 is set to a value at which matching (impedance matching) between the first λ/2 resonator 11 and the signal source 13 can be obtained. The shorter the distance x0, the smaller the coupling of the first λ/2 resonator 11 with the signal source 13.

[Specific Configuration Example of Wireless Communication Antenna]

The sixth (A) and (B) drawings show a specific configuration example of the wireless communication antenna shown in Fig. 1. For example, a conductor having a pattern as shown in the sixth (A) and (B) is formed on the two opposing surfaces of the flat dielectric substrate. For example, a conductor pattern of the sixth (A) pattern is formed on the upper surface of the dielectric substrate, and a conductor pattern of the sixth (B) is formed on the bottom surface. The conductor pattern of the sixth (A) diagram has a first conductor pattern constituting the first λ/2 resonator 11 at the center portion, and is formed in a semicircular shape at both ends (open ends) of the first conductor pattern. The electrode pattern of the first capacitor electrode 21 of the capacitor 20 and the electrode pattern of the first capacitor electrode 31 of the second capacitor 30. The conductor pattern of the sixth (B) has the same structure, and has a second conductor pattern constituting the second λ/2 resonator 12 at the center portion, and semicircle at both ends (open ends) of the second conductor pattern. The electrode pattern of the first capacitor electrode 22 of the first capacitor 20 and the electrode pattern of the second capacitor electrode 32 of the second capacitor 30 are formed in a form.

Fig. 7 is a view showing the result of simulating the state of the current vector in the fundamental resonance mode of the specific configuration example shown in Figs. 6(A) and (B). As shown in Fig. 7, it is known that the first λ/2 resonator 11 and the second λ/2 resonator 12 flow. The current is in the opposite direction.

[Configuration Example of Wireless Communication Device]

In the case of constructing a wireless communication system, in order to prevent electromagnetic waves from leaking to a distant place, the wireless communication antenna shown in Fig. 1 may constitute at least the antenna on the transmitting side. In the case where two antennas are bidirectionally communicated with each other, two antennas may be configured by the wireless communication antenna shown in Fig. 1 . Here, an example of a wireless communication device using two antennas having substantially the same structure is shown.

Fig. 8 is a view showing an example of a wireless communication device using the wireless communication antenna shown in Fig. 1. The wireless communication device includes a first antenna 1 and a second antenna 2. This first antenna has a flat first dielectric substrate 5. The second antenna 2 has a flat second dielectric substrate 6. At the time of communication, the first dielectric substrate 5 and the second dielectric substrate 6 are arranged to face each other with a space d (for example, from several millimeters to several centimeters).

A conductor having a pattern shown in Figs. 9(A) and (B) is formed on the first surface (upper surface) and the second surface (bottom surface) facing the first dielectric substrate 5. A conductor having the same pattern is formed on the first surface (upper surface) and the second surface (bottom surface) of the second dielectric substrate 6 facing each other. More specifically, the conductor pattern of the ninth (A) diagram is formed on the upper surface of the first dielectric substrate 5, and the conductor pattern shown in Fig. 9(B) is formed on the bottom surface. The conductor pattern of the ninth (B) drawing is formed on the upper surface of the second dielectric substrate 6, and the conductor pattern shown in Fig. 9(A) is formed on the bottom surface.

Similarly to the conductor pattern of the sixth (A) diagram, the conductor pattern of the ninth (A) diagram has the first conductor line pattern constituting the first λ/2 resonator 11 at the center portion, and is in the first conductor line pattern. Both ends (open end), points The electrode pattern of the first capacitor electrode 21 of the first capacitor 20 and the electrode pattern of the first capacitor electrode 31 of the second capacitor 30 are formed in a semicircular shape. As the conductor pattern of the ninth (A) diagram, for example, a line pattern which is a first connection line 15 for connecting one end of the signal source 13 (Fig. 4) is formed. One end of the line pattern to be the first connecting line 15 is connected to the first conductor line pattern of the center portion. Further, as described above, in order to obtain impedance matching between the first λ/2 resonator 11 and the signal source 13, one end of the line pattern of the first connection line 15 and the first conductor that constitutes the first λ/2 resonator 11 are provided. The center position of the line pattern is preferably connected to a position separated by a distance x0.

Similarly to the conductor pattern of the sixth (B) diagram, the conductor pattern of the ninth (B) diagram has the second conductor line pattern constituting the second λ/2 resonator 12 at the center portion, and is in the second conductor line pattern. The electrode patterns of the second capacitor electrode 22 of the first capacitor 20 and the electrode pattern of the second capacitor electrode 32 of the second capacitor 30 are formed in a semicircular shape at both ends (open ends). As the conductor pattern of the ninth (B) diagram, for example, a line pattern to be connected to the second connection line 14 at the other end of the signal source 13 (fourth diagram) and an electrode pattern to be the ground electrode 18 are formed. One end of the line pattern that becomes the second connection line 14 is connected to the second conductor line pattern of the center portion. Further, it is preferable that one end of the line pattern of the second connection line 14 is connected to the center position of the second conductor line pattern constituting the second λ/2 resonator 12.

In the wireless communication device, for example, the first antenna 1 can be used as a transmission antenna, and the second antenna 2 can be operated as a receiving antenna that receives reception of a signal transmitted from the first antenna 1. Further, both of the first antenna 1 and the second antenna 2 may be used as a transmission/reception antenna, and signals may be transmitted and received bidirectionally between the first antenna 1 and the second antenna 2.

[Modification of a specific configuration example of the antenna for wireless communication]

Fig. 10 is a view showing a first modification of the specific configuration of the wireless communication antenna shown in Fig. 1. In the first modification, for example, a conductor having a pattern as shown in FIG. 10 is formed in one surface of a flat dielectric substrate. As shown in Fig. 10, the first conductor line pattern constituting the first λ/2 resonator 11 and the second conductor line pattern constituting the second λ/2 resonator 12 are formed in parallel in the same plane. In the both ends (open ends) of the first conductor pattern, the electrode pattern of the first capacitor electrode 21 of the first capacitor 20 and the first capacitor 30 are formed on the side opposite to the second conductor line pattern. The electrode pattern of the capacitor electrode 31. These electrode patterns are formed in a difference from the first conductor line pattern. In the both ends (open ends) of the second conductor line pattern constituting the second λ/2 resonator 12, the electrodes of the second capacitor electrode 22 of the first capacitor 20 are formed on the side opposite to the first conductor line pattern. The pattern and the electrode pattern of the second capacitor electrode 32 of the second capacitor 30. These electrode patterns are formed in a difference from the second conductor line pattern segment.

In the configuration example of FIG. 10, the first capacitor 20 is formed by the electrode pattern of the first capacitor electrode 21 and the electrode pattern of the second capacitor electrode 22 facing each other at a predetermined interval in the same plane. In the same plane, the second capacitor 30 is formed by the electrode pattern of the first capacitor electrode 31 and the electrode pattern of the second capacitor electrode 32 facing each other with a predetermined interval therebetween.

Fig. 11 shows a second modification. The second modification is the same as the configuration example of Fig. 10. The basic structure of the second modification is the same as the configuration example of Fig. 10, but constitutes the first capacitor 20 and the second capacitor. In the second modification, the electrode pattern of the first capacitor electrode 21 and the electrode pattern of the second capacitor electrode 22 are each formed in a comb-tooth shape, and the comb-shaped line portion is interposed. The second capacitor 30 is an interdigital type line structure in which the intervals are alternately opposed. In the second modification, the electrode pattern constituting the first capacitor 20 and the second capacitor 30 is formed into an interdigital type line structure, and the relative capacitance is increased to form a larger capacitance. Therefore, the entire antenna can be made small.

Fig. 12 shows a third modification. In the third modification, the first conductor line pattern constituting the first λ/2 resonator 11 and the second conductor line pattern constituting the second λ/2 resonator 12 are formed in parallel on the slab, as in the configuration example of FIG. One surface of the dielectric substrate. In the third modification, the first capacitor 20 and the second capacitor 30 are constituted by capacitive elements that are not electrically connected to the first λ/2 resonator 11 and the second λ/2 resonator 12, instead of the electrode pattern of the conductor. The above is different from the configuration example of Fig. 10. Specifically, the open end of one of the first λ/2 resonator 11 (first conductor line pattern) and the open end of the second λ/2 resonator 12 (second conductor line pattern) are connected as the first The first wafer capacitor 41 of the capacitor 20. Further, the other open end of the first λ/2 resonator 11 (first conductor line pattern) facing the opposite side and the other open end of the second λ/2 resonator 12 (second conductor line pattern) are connected as the second The second wafer capacitor 42 of the capacitor 30. In the third modification, since the first capacitor 20 and the second capacitor 30 are formed not by the electrode pattern of the conductor but by the capacitor element, for example, a larger capacitance can be formed than the configuration example of FIG. 10 . The entire antenna can be miniaturized.

The thirteenth (A) to (C) diagram shows a fourth modification. For example, the conductors of the pattern shown in Figs. 13(A) and (B) are formed on the opposite faces of the flat dielectric substrate. Fig. 13(C) shows a state in which the conductor patterns shown in Figs. 13(A) and (B) are superimposed (opposed). For example, the conductor pattern of the thirteenth (B) drawing is formed on the upper surface of the dielectric substrate, and the conductor pattern of the thirteenth (A) drawing is formed on the bottom surface. As the conductor pattern of the thirteenth (A) diagram, the first conductor line pattern constituting the first λ/2 resonator 11 and the second conductor line pattern constituting the second λ/2 resonator 12 are formed in parallel. The conductor pattern of the 13th (B) diagram is open to one of the first λ/2 resonator 11 (first conductor line pattern) and the second λ/2 resonator 12 (second conductor line pattern). An electrode pattern of the first capacitor electrode 33 is formed at a position corresponding to the open end. Therefore, the first capacitor 20 is formed between the two opposing surfaces of the dielectric substrate. Further, at a position corresponding to the other open end of the first λ/2 resonator 11 (first conductor line pattern) and the other open end of the second λ/2 resonator 12 (second conductor line pattern), The electrode pattern of the second capacitor electrode 34 is formed. Therefore, the second capacitor 30 is formed between the two opposing surfaces of the dielectric substrate. According to the fourth modification, since the capacitance is formed between the two opposing surfaces, a larger capacitance can be formed than in the case where the capacitor is formed in one surface as shown in the configuration example of Fig. 10, for example. The entire antenna can be miniaturized.

The fourteenth (A) to (C) diagram shows a fifth modification. For example, the conductors of the pattern shown in Figs. 14(A) and (B) are formed on the opposite faces of the flat dielectric substrate. Fig. 14(C) shows a state in which the conductor patterns shown in Figs. 14(A) and (B) are overlapped (opposed). For example, the conductor pattern of the 14th (B) pattern is formed on the upper surface of the dielectric substrate, and the 14th (A) The conductor pattern of the figure is formed on the bottom surface. As the conductor pattern of the 14th (A) diagram, the second conductor line pattern constituting the second λ/2 resonator 12 is formed, and the first capacitor 20 is formed at both ends (open ends) of the second conductor line pattern. The electrode pattern of the capacitor electrode 22 and the electrode pattern of the second capacitor electrode 32 of the second capacitor 30 are formed in a C shape as a whole. As the conductor pattern of the 14th (B)th diagram, the first conductor line pattern constituting the first λ/2 resonator 11 is formed, and the first capacitor 20 is formed at both ends (open ends) of the first conductor line pattern. The electrode pattern of the capacitor electrode 21 and the electrode pattern of the first capacitor electrode 31 of the second capacitor 30 are formed in a C-shape that is bilaterally symmetrical with the conductor pattern of the 14th (A) diagram. According to the fifth modification, since the capacitance is formed between the two opposing surfaces, a larger capacitance can be formed than in the case where the capacitor is formed in one surface as shown in the configuration example of FIG. 10, for example. The entire antenna can be miniaturized.

The 15th (A) to (C) diagram shows a sixth modification. For example, the conductors of the pattern shown in Figs. 15(A) and (B) are formed on the opposite faces of the flat dielectric substrate. Fig. 15(C) shows a state in which the conductor patterns shown in Figs. 15(A) and (B) are superimposed (opposed). For example, the conductor pattern of the fifteenth (B) drawing is formed on the upper surface of the dielectric substrate, and the conductor pattern of the fifteenth (A) drawing is formed on the bottom surface. As the conductor pattern of the fifteenth (A) diagram, the second conductor line pattern constituting the second λ/2 resonator 12 is formed, and the first capacitor 20 is formed at both ends (open ends) of the second conductor line pattern. The electrode pattern of the capacitor electrode 22 and the electrode pattern of the second capacitor electrode 32 of the second capacitor 30 are formed in an I-shape as a whole. As the conductor pattern of the fifteenth (B) diagram, the first conductor constituting the first λ/2 resonator 11 is formed In the line pattern, the electrode pattern of the first capacitor electrode 21 of the first capacitor 20 and the electrode pattern of the first capacitor electrode 31 of the second capacitor 30 are formed integrally at both ends (open ends) of the first conductor pattern. I-shaped. According to the sixth modification, since the capacitance is formed between the two opposing surfaces, a larger capacitance can be formed than in the case where the capacitor is formed in one surface as shown in the configuration example of FIG. 10, for example. The entire antenna can be miniaturized.

The sixteenth (A) to (C) diagram shows a seventh modification. For example, the conductors of the pattern shown in Figs. 16(A) and (B) are formed on the opposite faces of the flat dielectric substrate. Fig. 16(C) shows a state in which the conductor patterns shown in Figs. 16(A) and (B) are overlapped (opposed). For example, the conductor pattern of the 16th (B)th pattern is formed on the upper surface of the dielectric substrate, and the conductor pattern of the 16th (A) pattern is formed on the bottom surface. As a conductor pattern of the 16th (A) diagram, a second conductor line pattern constituting the curved structure of the second λ/2 resonator 12 is formed, and at both ends (open ends) of the second conductor line pattern of the curved structure, The electrode pattern of the second capacitor electrode 22 of the first capacitor 20 and the electrode pattern of the second capacitor electrode 32 of the second capacitor 30 are formed. As the conductor pattern of the 16th (B)th diagram, the first conductor line pattern constituting the curved structure of the first λ/2 resonator 11 is formed, and at both ends (open ends) of the first conductor line pattern of the curved structure, The electrode pattern of the first capacitor electrode 21 of the first capacitor 20 and the electrode pattern of the first capacitor electrode 31 of the second capacitor 30 are formed. According to the seventh modification, since the capacitance is formed between the two opposing surfaces, a larger capacitance can be formed than in the case where the capacitor is formed in one surface as shown in the configuration example of FIG. 10, for example. The entire antenna can be miniaturized. Again, according to the first In the seventh modification, since the first and second conductor line patterns are formed in a curved structure, not only the directions of the currents i flowing between the first λ/2 resonator 11 and the second λ/2 resonator 12 are opposite to each other, but also The directions of the currents i flowing in the respective resonators also become opposite to each other. Therefore, the current i flowing to the first and second λ/2 resonators 11 and 12 is more effectively canceled than in the case where the first and second conductor line patterns are simply formed in a straight line, and the radiation in the distance is distant. The electricity becomes smaller.

The seventeenth (A) to (C) diagram shows an eighth modification. For example, the conductors of the pattern shown in Figs. 17(A) and (B) are formed on the opposite faces of the flat dielectric substrate. Fig. 17(C) shows a state in which the conductor patterns shown in Figs. 17(A) and (B) are superimposed (opposed). For example, the conductor pattern of the 17th (B)th pattern is formed on the upper surface of the dielectric substrate, and the conductor pattern of the 17th (A) pattern is formed on the bottom surface. In the eighth modification, the first conductor line pattern constituting the first λ/2 resonator 11 and the second conductor line pattern constituting the second λ/2 resonator 12 have a curved structure as in the seventh modification.

In the eighth modification, the first capacitor 20 and the second capacitor 30 are formed by a capacitor element which is not an electrode pattern of a conductor but an electric component different from the first λ/2 resonator 11 and the second λ/2 resonator 12 . This is different from the seventh modification. Specifically, the first wafer capacitor 41 of the first capacitor 20 and one of the open ends of the first λ/2 resonator 11 (the end portion 21A on the side of the first conductor line pattern) and the second λ/2 resonator 12 An open end (end portion 22A on one side of the second conductor line pattern) is connected. The end portion 22A on the side of the second conductor line pattern is connected to the first wafer capacitor 41 via the first connection conductor 22B penetrating the dielectric substrate. Further, the second wafer capacitor 42 as the second capacitor 30 and the first λ/2 resonator 11 The other open end (the other end portion 31A of the first conductor line pattern) and the other open end of the second λ/2 resonator 12 (the other end portion 32A of the second conductor line pattern) are connected. The other end portion 32A of the second conductor line pattern is connected to the second wafer capacitor 42 via the second connection conductor 32B penetrating the dielectric substrate. In the eighth modification, since the first capacitor 20 and the second capacitor 30 are formed not by the electrode pattern of the conductor but by the capacitor element, for example, compared with the seventh modification, it is possible to form a larger area than the seventh modification. capacitance.

The eighteenth (A) to (C) diagram shows a ninth modification. For example, the conductors of the pattern shown in Figs. 18(A) and (B) are formed on the opposite faces of the flat dielectric substrate. Fig. 18(C) shows a state in which the conductor patterns shown in Figs. 18(A) and (B) are superimposed (opposed). For example, the conductor pattern of the 18th (B)th pattern is formed on the upper surface of the dielectric substrate, and the conductor pattern of the 18th (A) figure is formed on the bottom surface. As the conductor pattern of the 18th (A) diagram, a second conductor line pattern constituting the spiral structure of the second λ/2 resonator 12 is formed, and at both ends (open ends) of the second conductor line pattern of the spiral structure, The electrode pattern of the second capacitor electrode 22 of the first capacitor 20 and the electrode pattern of the second capacitor electrode 32 of the second capacitor 30 are formed. As the conductor pattern of the 18th (B)th diagram, the first conductor line pattern constituting the spiral structure of the first λ/2 resonator 11 is formed, and at both ends (open ends) of the first conductor line pattern of the spiral structure, The electrode pattern of the first capacitor electrode 21 of the first capacitor 20 and the electrode pattern of the first capacitor electrode 31 of the second capacitor 30 are formed. According to the ninth modification, since the capacitance is formed between the two opposing surfaces, it can be formed as compared with the case where the capacitor is formed in one plane as shown in the configuration example of Fig. 10, for example. A larger capacitance allows the antenna to be smaller overall. Further, according to the ninth modification, since the first and second conductor line patterns are formed in a spiral structure, not only the direction of the current i flowing between the first λ/2 resonator 11 and the second λ/2 resonator 12 is obtained. The opposite of each other, and the directions of the currents i flowing in the respective resonators become opposite to each other. Therefore, the current i flowing to the first and second λ/2 resonators 11 and 12 is more effectively canceled than in the case where the first and second conductor line patterns are simply formed in a straight line, and the radiation in the distance is distant. The electricity becomes smaller.

The 19th (A)-(C) figure shows the 10th modification. For example, the conductors of the pattern shown in Figs. 19(A) and (B) are formed on the opposite faces of the flat dielectric substrate. Fig. 19(C) shows a state in which the conductor patterns shown in Figs. 19(A) and (B) are overlapped (opposed). For example, the conductor pattern of the 19th (B)th pattern is formed on the upper surface of the dielectric substrate, and the conductor pattern of the 19th (A) diagram is formed on the bottom surface. In the tenth modification, the first conductor line pattern constituting the first λ/2 resonator 11 and the second conductor line pattern constituting the second λ/2 resonator 12 have a spiral structure as in the ninth modification.

In the tenth modification, the first capacitor 20 and the second capacitor 30 are constituted by a capacitor element which is not an electrode pattern of a conductor but an electric component different from the first λ/2 resonator 11 and the second λ/2 resonator 12 . This is different from the ninth modification. Specifically, the first wafer capacitor 41 of the first capacitor 20 and one of the open ends of the first λ/2 resonator 11 (the end portion 21A on the side of the first conductor line pattern) and the second λ/2 resonator 12 An open end (end portion 22A on one side of the second conductor line pattern) is connected. The end portion 22A on one side of the second conductor line pattern passes through the first through the dielectric substrate The 1 connection conductor 22B is connected to the first wafer capacitor 41. Further, the second wafer capacitor 42 of the second capacitor 30 and the other open end of the first λ/2 resonator 11 (the other end portion 31A of the first conductor line pattern) and the second λ/2 resonator 12 The other open end (the end 32A on the other side of the second conductor line pattern) is connected. The other end portion 32A of the second conductor line pattern is connected to the second wafer capacitor 42 via the second connection conductor 32B penetrating the dielectric substrate. In the tenth modification, since the first capacitor 20 and the second capacitor 30 are formed not by the electrode pattern of the conductor but by the capacitance element, for example, it is possible to form a larger area than the ninth modification. capacitance.

<Second embodiment>

Next, a wireless communication antenna according to a second embodiment of the present invention will be described. In addition, the same components as those of the wireless communication antenna of the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[Basic composition of antenna for wireless communication]

Fig. 20 is a view showing the basic configuration of a wireless communication antenna according to a second embodiment of the present invention. The wireless communication antenna includes a first λ/4 resonator 51 (first resonator), a second λ/4 resonator 52 (second resonator), and a first capacitor 20.

One end of each of the first λ/4 resonator 51 and the second λ/4 resonator 52 serves as an open end, and the other end serves as a short-circuited end, and is disposed in parallel with each other so that the open ends of each other face each other, and the short-circuit ends of each other The opposite direction. The first capacitor 20 is connected between the open ends of the first λ/4 resonator 51 and the second λ/4 resonator 52. The first capacitor 20 The capacitor electrode 21 is connected to the open end of the first λ/4 resonator 51. The second capacitor electrode 22 of the first capacitor 20 is connected to the open end of the second λ/4 resonator 52.

[Basic actions and functions of antennas for wireless communication]

The structure of the wireless communication antenna of the present embodiment is a portion that becomes zero potential at the time of resonance (if the capacitance Cint1 of the first capacitor 20 is the same as the capacitance Cint2 of the second capacitor 30, it is the physical center line 16 of the resonator) The wireless communication antenna of the first embodiment is divided into a half structure. Basically, the same functions and effects as those of the wireless communication antenna of the first embodiment can be obtained.

Fig. 21 is a diagram showing the state of charge distribution and current vector of the antenna for wireless communication in the fundamental resonance mode (the lowest resonance mode of the resonance frequency). In the wireless communication antenna, the first and second λ/4 resonators 51 and 52 are arranged in parallel with each other so that the open ends thereof are opposed to each other, and the opposite open ends are connected via the first capacitor 20. In the fundamental resonance mode, the electric field distribution of the first λ/4 resonator 51 and the second λ/4 resonator 52 are opposite. Therefore, in the basic resonance mode, as shown in FIG. 21, the first λ/4 resonator 51 and the second λ/4 resonator 52 have opposite directions of current i (which are differential resonance modes). Therefore, in the fundamental resonance mode, the current flowing between the first λ/4 resonator 51 and the second λ/4 resonator 52 cancels each other, and the radiant power in the far side becomes small. Therefore, with respect to signal transmission in the frequency band corresponding to the fundamental resonance mode, it is possible to prevent leakage of signals (electromagnetic waves) to a distant place.

The wireless communication antenna of the present embodiment is also used as a coupler in the same manner as the wireless communication antenna of the first embodiment. In the wireless communication antenna having the configuration shown in Fig. 20, when the antennas are close to each other, the radiant power is made as small as possible, and a wireless communication device that transmits only by reactance coupling can be realized. Therefore, high-speed wireless communication at a short distance can be realized while avoiding interference with the frequency and frequency bandwidth of the existing wireless communication system.

[Connection method with signal source (excitation method of resonator)]

Fig. 22 is a view showing an example of a method of exciting a resonator in the wireless communication antenna shown in Fig. 20. In the first example, the first λ/4 resonator 51 is connected to one end (first connection line 15) of the signal source 13 at a position 57 at a predetermined distance x0 from the position 56 of the short-circuit end, and the other end of the signal source 13 ( The second connecting line 14) is grounded. Further, the other end (second connection line 14) of the signal source 13 may be connected to, for example, the short-circuited end of the second λ/4 resonator 52.

The distance x0 in Fig. 22 is set to a value at which the matching (impedance matching) between the first λ/4 resonator 51 and the signal source 13 can be obtained. The shorter the distance x0, the smaller the coupling of the first λ/4 resonator 51 with the signal source 13.

[Specific Configuration Example of Wireless Communication Antenna]

The structure of the wireless communication antenna of the present embodiment basically divides the wireless communication antenna of the first embodiment into half, and as a specific configuration example, the sixth and tenth to nineteenth drawings are created. The structure of each specific configuration example of the first embodiment may be divided into a half structure. For example, when the configuration example shown in Fig. 15 is divided into half, the structure as shown in Fig. 23 can be obtained.

For example, a conductor having a pattern as shown in Figs. 23(A) and (B) is formed on the two opposing surfaces of the flat dielectric substrate. 23(C) chart A state in which the conductor patterns shown in the 23rd (A) and (B) are overlapped (opposed). For example, the conductor pattern of the 23 (B) drawing is formed on the upper surface of the dielectric substrate, and the conductor pattern of the 23 (A) drawing is formed on the bottom surface. As the conductor pattern of the 23rd (B)th diagram, the first conductor line pattern constituting the first λ/4 resonator 51 is formed, and the first capacitor 20 is formed at one end (open end) of the first conductor line pattern. 1 electrode pattern of the capacitor electrode 21. As the conductor pattern of the 23rd (A) diagram, the second conductor line pattern constituting the second λ/4 resonator 52 is formed, and the first capacitor 20 is formed at one end (open end) of the second conductor line pattern. 2 electrode pattern of the capacitor electrode 22. Therefore, the first capacitor 20 is formed between the two opposing faces of the dielectric substrate.

<Other Embodiments>

The present invention is not limited to the above embodiments, and various modifications can be made.

For example, the wireless communication antenna of each of the above embodiments is used not only for transmitting/receiving signal transmission of analog signals or digital signals, but also for power transmission/reception power transmission devices.

Further, in each of the above-described embodiments, a configuration example in which a resonator formed in accordance with a conductor line pattern is formed on a dielectric substrate will be described. However, for example, a lumped constant element having an electrical length of λ/2 or λ/4 may be used. Form a resonator. Further, in each of the above-described embodiments, a configuration example in which the conductor pattern is formed on at least one of the upper surface and the bottom surface of the dielectric substrate will be described. However, for example, the dielectric substrate may be a multilayer substrate, and a conductor pattern may be formed on the inner layer.

1‧‧‧1st antenna

2‧‧‧2nd antenna

3‧‧‧Transmission circuit

4‧‧‧ receiving circuit

5‧‧‧1st dielectric substrate

6‧‧‧2nd dielectric substrate

11‧‧‧1λ/2 resonator

12‧‧‧2λ/2 resonator

13‧‧‧Signal source

14‧‧‧2nd connection line

15‧‧‧1st connection line

16‧‧‧ center line

17‧‧‧The distance from the distance x0

18‧‧‧Ground electrode

20‧‧‧1st capacitor

21‧‧‧1st capacitor electrode

End of 21A‧‧‧ side

22‧‧‧2nd capacitor electrode

End of 22A‧‧‧ side

22B‧‧‧1st connecting conductor

30‧‧‧2nd capacitor

31‧‧‧1st capacitor electrode

31A‧‧‧End of the other side

32‧‧‧2nd capacitor electrode

32A‧‧‧End of the other side

32B‧‧‧2nd connecting conductor

33‧‧‧1st capacitor electrode

34‧‧‧2nd capacitor electrode

41‧‧‧1st chip capacitor

42‧‧‧2nd wafer capacitor

51‧‧‧1st λ/4 resonator

52‧‧‧2nd λ/4 resonator

56‧‧‧ Location of the short-circuit end

57‧‧‧Location distance x0

I‧‧‧current

Fig. 1 is a diagram showing the days of wireless communication in the first embodiment of the present invention. A circuit diagram of the basic structure of the line.

Fig. 2 is an explanatory view showing states of charge distribution and current vector in the fundamental resonance mode of the wireless communication antenna shown in Fig. 1.

Fig. 3(A) is an explanatory view showing the state of the electric field distribution and the current vector of the first resonator in the basic resonance mode of the wireless communication antenna shown in Fig. 1, and Fig. 3(B) shows the basic An explanatory diagram of the state of the electric field distribution and the current vector of the second resonator in the resonance mode.

Fig. 4 is a view showing a configuration of a first example of a method of exciting a resonator in the wireless communication antenna shown in Fig. 1.

Fig. 5 is a view showing a configuration of a second excitation method of the resonator of the first example of the method of exciting the resonator in the wireless communication antenna shown in Fig. 1.

6(A) and 6(B) are plan views showing a specific configuration example of the wireless communication antenna shown in Fig. 1.

Fig. 7 is a characteristic diagram showing the result of simulating the state of the current vector in the fundamental resonance mode of the specific configuration example shown in Fig. 6.

Fig. 8 is a perspective view showing an example of a wireless communication device using the wireless communication antenna shown in Fig. 1.

9(A) and 9(B) are plan views showing the structure of a conductor pattern of the wireless communication device shown in Fig. 8.

Fig. 10 is a plan view showing a first modification of the specific configuration of the wireless communication antenna shown in Fig. 1.

Fig. 11 is a plan view showing a second modification of the specific configuration of the wireless communication antenna shown in Fig. 1.

Figure 12 is a diagram showing the specifics of the wireless communication antenna shown in Fig. 1. A plan view of a third modification of the configuration.

13(A) to (C) are plan views showing a fourth modification of the specific configuration of the wireless communication antenna shown in Fig. 1.

14(A) to (C) are plan views showing a fifth modification of the specific configuration of the wireless communication antenna shown in Fig. 1.

15(A) to (C) are plan views showing a sixth modification of the specific configuration of the wireless communication antenna shown in Fig. 1.

16(A) to (C) are plan views showing a seventh modification of the specific configuration of the wireless communication antenna shown in Fig. 1.

17(A) to (C) are plan views showing an eighth modification of the specific configuration of the wireless communication antenna shown in Fig. 1.

18(A) to (C) are plan views showing a ninth modification of the specific configuration of the wireless communication antenna shown in Fig. 1.

19(A) to (C) are plan views showing a tenth modification of the specific configuration of the wireless communication antenna shown in Fig. 1.

Fig. 20 is a circuit diagram showing a basic configuration of a wireless communication antenna according to a second embodiment of the present invention.

Fig. 21 is an explanatory view showing a state of charge distribution and a current vector in the fundamental resonance mode of the wireless communication antenna shown in Fig. 20.

Fig. 22 is a view showing the configuration of a method of exciting a resonator in the wireless communication antenna shown in Fig. 20.

23(A) to (C) are plan views showing a specific configuration example of the wireless communication antenna shown in Fig. 20.

11‧‧‧1λ/2 resonator

12‧‧‧2λ/2 resonator

20‧‧‧1st capacitor

21‧‧‧1st capacitor electrode

22‧‧‧2nd capacitor electrode

30‧‧‧2nd capacitor

31‧‧‧1st capacitor electrode

32‧‧‧2nd capacitor electrode

Claims (11)

An antenna for wireless communication, comprising: first and second resonators each having an open end and arranged in parallel with each other, an open end of the first resonator and an open end of the second resonator And a capacitor that connects the open end of the first resonator facing each other and the open end of the second resonator. The wireless communication antenna according to claim 1, wherein the first and second resonators propagate signals in a resonance mode in which the directions of the flowing currents are opposite to each other. The wireless communication antenna according to claim 1, wherein the first and second resonators are constituted by a line resonator using a conductor line, and the capacitor is formed by an electrode pattern, wherein the electrode pattern is A conductor formed on the open end side of the first and second resonators. The wireless communication antenna according to claim 1, wherein the capacitor is a capacitive element of an element different from the first and second resonators. The wireless communication antenna according to any one of claims 1 to 4, wherein the first resonator is a first λ/2 resonator having open ends, and the second resonator is open at both ends 2λ/2 resonator; The capacitor is composed of a first capacitor and a second capacitor; the first capacitor is connected to one open end of the first λ/2 resonator and one open end of the second λ/2 resonator; and the second capacitor is The other open end of the first λ/2 resonator and the other open end of the second λ/2 resonator are connected. The wireless communication antenna according to claim 5, wherein in the first λ/2 resonator, one end of the signal source is connected to a position at a predetermined distance from the resonance center position, and the other end of the signal source is grounded. The wireless communication antenna according to claim 5, wherein the first λ/2 resonator is connected to one end of the signal source at a predetermined distance from the resonance center position, and is in the second λ/2 resonator. The resonance center position is connected to the other end of the aforementioned signal source. The wireless communication antenna according to any one of claims 1 to 4, wherein the first resonator has one end as an open end and the other end as a short-circuited first λ/4 resonator; and the second resonator One end is used as the open end, and the other end is used as the second λ/4 resonator of the short-circuit end. The wireless communication antenna according to claim 8, wherein one end of the signal source is connected to a position at a predetermined distance from the short-circuit end of the first λ/4 resonator, and the other end of the signal source is grounded. A wireless communication device having: a first antenna for transmitting a signal; and The second antenna receives a signal transmitted from the first antenna, and the first antenna includes first and second resonators, each of which has an open end and is arranged in parallel with each other in the first resonator. The open end and the open end of the second resonator face each other; and the capacitor is connected to the open end of the first resonator and the open end of the second resonator. The wireless communication device according to claim 10, wherein the first antenna further has a function of receiving a signal, and the second antenna further has a function of transmitting a signal, and the first antenna and the second antenna are The first antenna and the second antenna have first and second resonators each having an open end and arranged in parallel with each other to open the first resonator. And an open end of the second resonator facing the capacitor; and a capacitor connecting the open end of the first resonator and the open end of the second resonator.